IRIS Movie of the Day
At least once a week a movie of the Sun taken by NASA's Interface Region Imaging Spectrograph (IRIS) is posted by one of the scientists operating the instrument.
Sunspots and Flare Ribbons
Credit: IRIS, LMSAL/NASA, Jenna Samra (SAO)
This movie demonstrates several features of a flaring active region on the sun. The dark areas, which correspond to sunspots in the solar photosphere below, indicate regions that are densely packed with magnetic field lines entering and exiting the solar surface. Magnetic loops connecting the sunspots extend into the solar corona, where they become tangled, reconnect, and release energy in what is known as a solar flare. The bright "flare ribbons" that appear in the middle of the video are thought to be caused when particles accelerated downward by the flare collide with plasma in the chromosphere, temporarily intensifying the light emitted by the plasma.